Investigation of structure, thermal and dielectric study of Dy0.05Ba0.7Sr0.25TiO3/polystyrene nanocomposites

Abstract In the present study, Dy0.05Ba0.7Sr0.25TiO3 (Dy-BST) nanoparticles were prepared using the conventional solid-state reaction technique. Different volume fractions of Dy-BST (0, 5, 10, 15 & 20) were immersed in the polystyrene (PS) matrix, forming PS/Dy-BST nanocomposites, then their crystal structure, morphology, topography, thermal properties, electrical properties, breakdown voltage, and energy storage were investigated. X-ray diffraction (XRD) validates the cubic phase of Dy-BST nanoparticles incorporated in PS/Dy-BST nanocomposites. The size of Dy-BST nanoparticles was in the range (8–18 nm) using HRTEM. Incorporating Dy-BST NPs into the polymer matrix improved the thermal stability and limited the thermal degradation of the nanocomposite. The loading of Dy-BST in PS has a positive effect on dielectric properties and breakdown strength. The permittivity (ε′) enhanced from 2 to 10 at a constant frequency of 105 Hz while a relatively high loss (tanδ) decreased from 0.0015 to 0.0011 with the increase of Dy-BST content in the PS matrix. Finally, dielectric strengths of PS/Dy-BST nanocomposites were evaluated using high voltage testing; then their corresponding energy densities were obtained. The energy density increased to 133% at a 10 vol.% loading of Dy-BST compared to pure polystyrene.